title: HLA-G and pregnancy adverse outcomes.
abstract: There is growing evidence that pregnancy complications such as preeclampsia, recurrent pregnancy loss (RPL), IUGR, and premature birth could be associated with abnormal immunologic interactions at the fetal-maternal interface. The restricted expression of HLA-G to the subpopulation of trophoblast cells which invade the uterus has generated much interest. The alternative splicing of HLA-G primary transcript, gives origin to seven isoforms, including both membrane-bound forms (HLA-G1, G2, G3, G4) and soluble forms (sHLA-G: sHLA-G5, G6, G7). sHLA-G consists predominantly of sHLA-G1 after its shedding by metalloproteinases, and secreted sHLA-G5 representing the quantitatively dominating and full-length isoforms. HLA-G expression and HLA-G genetic variations in both the mother and the embryo/fetus may be important for pregnancy outcome. It is also intuitively apparent that a gene with putative immunosuppressive and immunotolerant potential might be functional in both the mother and the embryo/fetus/placenta. Reduced or aberrant HLA-G expression seems to be associated with certain complications of pregnancy, among which preeclampsia and possibly the risk of miscarriage, and that this may be further linked to HLA-G polymorphisms. Most of the studies aimed at assessing the role of HLA-G in pregnant diseases have considered only the maternal genotype and ignored the contribution of the fetus. In this regard, the mother, placenta and the fetus form a synthesis. Therefore, studies on placental diseases should address HLA-G expression and genetic variations also to the fetus/placenta.
authors.affiliation: Dipartimento di Biochimica, Biologia e Genetica, Università Politecnica delle Marche, via Ranieri 65, Ancona 60131, Italy. moniacecati@interfree.it
authors.forename: Monia
authors.initials: M
authors.lastname: Cecati
authors.forename: Stefano R
authors.initials: SR
authors.lastname: Giannubilo
authors.forename: Monica
authors.initials: M
authors.lastname: Emanuelli
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Tranquilli
authors.forename: Franca
authors.initials: F
authors.lastname: Saccucci
mesh_terms: D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D011256:Pregnancy Outcome
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I